Closes#2868
- Uses jQuery's `.fadeOut` whenever a popover is closed.
- Reordered `gh-popover`'s code into something a bit more logical and, if
I may, pretty
- Renamed `open` property into `isOpen`. `isOpen` should only be
manipulated via `close()` and `open()`
- Added `closing` property to help track state in the case of rapid clicks
on a popover's button, allowing us to abort
` Added `open()` function
Closes#2418, #2714
Ref #2446, #2565
- Added and injected `popover` service to globally control popovers
- Added `gh-popover-button` component
- Added `popover-mixin` for popover and popover-buttons to mixin
- Added body-event-listener mixin for popover service to watch for body
clicks with
- Post settings and post save button both now use `gh-popover`
- Added hacks to `ember-hacks.css` to make popovers work until ghost-ui
consolidates functionality
